1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * kernel/lockdep_internals.h 4 * 5 * Runtime locking correctness validator 6 * 7 * lockdep subsystem internal functions and variables. 8 */ 9 10 /* 11 * Lock-class usage-state bits: 12 */ 13 enum lock_usage_bit { 14 #define LOCKDEP_STATE(__STATE) \ 15 LOCK_USED_IN_##__STATE, \ 16 LOCK_USED_IN_##__STATE##_READ, \ 17 LOCK_ENABLED_##__STATE, \ 18 LOCK_ENABLED_##__STATE##_READ, 19 #include "lockdep_states.h" 20 #undef LOCKDEP_STATE 21 LOCK_USED, 22 LOCK_USAGE_STATES 23 }; 24 25 #define LOCK_USAGE_READ_MASK 1 26 #define LOCK_USAGE_DIR_MASK 2 27 #define LOCK_USAGE_STATE_MASK (~(LOCK_USAGE_READ_MASK | LOCK_USAGE_DIR_MASK)) 28 29 /* 30 * Usage-state bitmasks: 31 */ 32 #define __LOCKF(__STATE) LOCKF_##__STATE = (1 << LOCK_##__STATE), 33 34 enum { 35 #define LOCKDEP_STATE(__STATE) \ 36 __LOCKF(USED_IN_##__STATE) \ 37 __LOCKF(USED_IN_##__STATE##_READ) \ 38 __LOCKF(ENABLED_##__STATE) \ 39 __LOCKF(ENABLED_##__STATE##_READ) 40 #include "lockdep_states.h" 41 #undef LOCKDEP_STATE 42 __LOCKF(USED) 43 }; 44 45 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE | 46 static const unsigned long LOCKF_ENABLED_IRQ = 47 #include "lockdep_states.h" 48 0; 49 #undef LOCKDEP_STATE 50 51 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE | 52 static const unsigned long LOCKF_USED_IN_IRQ = 53 #include "lockdep_states.h" 54 0; 55 #undef LOCKDEP_STATE 56 57 #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ | 58 static const unsigned long LOCKF_ENABLED_IRQ_READ = 59 #include "lockdep_states.h" 60 0; 61 #undef LOCKDEP_STATE 62 63 #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ | 64 static const unsigned long LOCKF_USED_IN_IRQ_READ = 65 #include "lockdep_states.h" 66 0; 67 #undef LOCKDEP_STATE 68 69 /* 70 * CONFIG_LOCKDEP_SMALL is defined for sparc. Sparc requires .text, 71 * .data and .bss to fit in required 32MB limit for the kernel. With 72 * CONFIG_LOCKDEP we could go over this limit and cause system boot-up problems. 73 * So, reduce the static allocations for lockdeps related structures so that 74 * everything fits in current required size limit. 75 */ 76 #ifdef CONFIG_LOCKDEP_SMALL 77 /* 78 * MAX_LOCKDEP_ENTRIES is the maximum number of lock dependencies 79 * we track. 80 * 81 * We use the per-lock dependency maps in two ways: we grow it by adding 82 * every to-be-taken lock to all currently held lock's own dependency 83 * table (if it's not there yet), and we check it for lock order 84 * conflicts and deadlocks. 85 */ 86 #define MAX_LOCKDEP_ENTRIES 16384UL 87 #define MAX_LOCKDEP_CHAINS_BITS 15 88 #define MAX_STACK_TRACE_ENTRIES 262144UL 89 #else 90 #define MAX_LOCKDEP_ENTRIES 32768UL 91 92 #define MAX_LOCKDEP_CHAINS_BITS 16 93 94 /* 95 * Stack-trace: tightly packed array of stack backtrace 96 * addresses. Protected by the hash_lock. 97 */ 98 #define MAX_STACK_TRACE_ENTRIES 524288UL 99 #endif 100 101 #define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS) 102 103 #define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5) 104 105 extern struct list_head all_lock_classes; 106 extern struct lock_chain lock_chains[]; 107 108 #define LOCK_USAGE_CHARS (1+LOCK_USAGE_STATES/2) 109 110 extern void get_usage_chars(struct lock_class *class, 111 char usage[LOCK_USAGE_CHARS]); 112 113 extern const char * __get_key_name(struct lockdep_subclass_key *key, char *str); 114 115 struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i); 116 117 extern unsigned long nr_lock_classes; 118 extern unsigned long nr_list_entries; 119 long lockdep_next_lockchain(long i); 120 unsigned long lock_chain_count(void); 121 extern int nr_chain_hlocks; 122 extern unsigned long nr_stack_trace_entries; 123 124 extern unsigned int nr_hardirq_chains; 125 extern unsigned int nr_softirq_chains; 126 extern unsigned int nr_process_chains; 127 extern unsigned int max_lockdep_depth; 128 extern unsigned int max_recursion_depth; 129 130 extern unsigned int max_bfs_queue_depth; 131 132 #ifdef CONFIG_PROVE_LOCKING 133 extern unsigned long lockdep_count_forward_deps(struct lock_class *); 134 extern unsigned long lockdep_count_backward_deps(struct lock_class *); 135 #else 136 static inline unsigned long 137 lockdep_count_forward_deps(struct lock_class *class) 138 { 139 return 0; 140 } 141 static inline unsigned long 142 lockdep_count_backward_deps(struct lock_class *class) 143 { 144 return 0; 145 } 146 #endif 147 148 #ifdef CONFIG_DEBUG_LOCKDEP 149 150 #include <asm/local.h> 151 /* 152 * Various lockdep statistics. 153 * We want them per cpu as they are often accessed in fast path 154 * and we want to avoid too much cache bouncing. 155 */ 156 struct lockdep_stats { 157 int chain_lookup_hits; 158 int chain_lookup_misses; 159 int hardirqs_on_events; 160 int hardirqs_off_events; 161 int redundant_hardirqs_on; 162 int redundant_hardirqs_off; 163 int softirqs_on_events; 164 int softirqs_off_events; 165 int redundant_softirqs_on; 166 int redundant_softirqs_off; 167 int nr_unused_locks; 168 int nr_redundant_checks; 169 int nr_redundant; 170 int nr_cyclic_checks; 171 int nr_cyclic_check_recursions; 172 int nr_find_usage_forwards_checks; 173 int nr_find_usage_forwards_recursions; 174 int nr_find_usage_backwards_checks; 175 int nr_find_usage_backwards_recursions; 176 177 /* 178 * Per lock class locking operation stat counts 179 */ 180 unsigned long lock_class_ops[MAX_LOCKDEP_KEYS]; 181 }; 182 183 DECLARE_PER_CPU(struct lockdep_stats, lockdep_stats); 184 extern struct lock_class lock_classes[MAX_LOCKDEP_KEYS]; 185 186 #define __debug_atomic_inc(ptr) \ 187 this_cpu_inc(lockdep_stats.ptr); 188 189 #define debug_atomic_inc(ptr) { \ 190 WARN_ON_ONCE(!irqs_disabled()); \ 191 __this_cpu_inc(lockdep_stats.ptr); \ 192 } 193 194 #define debug_atomic_dec(ptr) { \ 195 WARN_ON_ONCE(!irqs_disabled()); \ 196 __this_cpu_dec(lockdep_stats.ptr); \ 197 } 198 199 #define debug_atomic_read(ptr) ({ \ 200 struct lockdep_stats *__cpu_lockdep_stats; \ 201 unsigned long long __total = 0; \ 202 int __cpu; \ 203 for_each_possible_cpu(__cpu) { \ 204 __cpu_lockdep_stats = &per_cpu(lockdep_stats, __cpu); \ 205 __total += __cpu_lockdep_stats->ptr; \ 206 } \ 207 __total; \ 208 }) 209 210 static inline void debug_class_ops_inc(struct lock_class *class) 211 { 212 int idx; 213 214 idx = class - lock_classes; 215 __debug_atomic_inc(lock_class_ops[idx]); 216 } 217 218 static inline unsigned long debug_class_ops_read(struct lock_class *class) 219 { 220 int idx, cpu; 221 unsigned long ops = 0; 222 223 idx = class - lock_classes; 224 for_each_possible_cpu(cpu) 225 ops += per_cpu(lockdep_stats.lock_class_ops[idx], cpu); 226 return ops; 227 } 228 229 #else 230 # define __debug_atomic_inc(ptr) do { } while (0) 231 # define debug_atomic_inc(ptr) do { } while (0) 232 # define debug_atomic_dec(ptr) do { } while (0) 233 # define debug_atomic_read(ptr) 0 234 # define debug_class_ops_inc(ptr) do { } while (0) 235 #endif 236